J:

Here's another recipe from St. Patrick's Day (besides the
Corned Beef & Cabbage and Potato Leek Soup which you already
have). Colcannon is an Irish dish make with potatoes mashed
with cabbage. This makes a big batch so scale it down.

Colcannon

5 pounds potatoes
5 pounds cabbage (2 big heads) shredded
5 medium leeks, thinly sliced, white and pale green parts only
4 tablespoons butter or margerine
2 cups nonfat sour cream
salt and pepper to taste

In a heavy stock pot or dutch oven, saute the cabbage and leeks
in the butter until starting to brown, about 20-30 minutes,
stirring and scraping the mixture off the bottom. Scrub the
potatoes and cut into chunks. Boil, unpeeled, until soft
enough to mash. Drain and mash with cabbage mixture, sour
cream, and salt and pepper.